For instance, if a car driver slows down to let you cross the road, simply raising your hand in acknowledgement is enough to show that you appreciate the driver's consideration.

Dickon sat cross-legged with his rabbit asleep on his arm and a hand resting on the lamb's back.

As we were about to cross a busy street that was filled with traffic, you took my hand suddenly and shouted, "Hang on to me, Mom," then led me safely across.